Steve Yeager’s obsessive documentary on the making of “Pink Flamingos” with 300-pound transvestite Divine is arguably more entertaining than John Waters’ 1972 movie itself.Running time: 97 minutes. Not rated. At Anthology Film Archives, Second Avenue and Second Street.

JOHN Waters is one of the most important filmmakers of the last 30 years — not because his films are particularly well made, but because he explored taboo subjects that have long since entered the mainstream.

This is brought home beautifully in “Divine Trash,” a fascinating documentary about the Baltimore-based auteur’s early career in general, and his most notorious film, “Pink Flamingos,” in particular.

Director Steve Yeager, working as a TV cameraman in 1972, captured priceless footage of the then long-haired Waters and his 300-pound transvestite leading lady, Divine, during the underground film’s production.

Obsessive detail about Divine’s eye makeup, the film’s prop budget ($200 for a decrepit trailer that fell apart while being moved) and Waters’ guerrilla filmmaking tactics are arguably more interesting to watch at this point than “Pink Flamingos” itself.

Besides the poop on the movie’s notorious dog-excrement-eating scene, Yeager offers great interviews with Waters (who cites an early encounter with Howdy

Doody as a major influence), the late Divine, an aged Maryland state official who still regards Waters as a pornographer — and a minister who offered his church for showings of Waters’ first films.

“I’m just trying to give them a good time — and throw in a little shock value for their money,” says Waters, whose early efforts pushed the envelope of bad taste by depicting the recently widowed Jacqueline Kennedy and the suicide of talk-show icon Art Linkletter’s daughter Diane.